Digging in a little bit, I rsync'ed the repos from common-lisp.net. The _darcs/inventory file includes only the last 17 changes. More frighteningly, one of the checkpoints in _darcs/checkpoints looks corrupt:
$ gunzip --verbose -c 20090616162007-28748-931df2ed8b38d5ad8b6df25ef6f71a9657193d6a.gz > 20090616162007-28748-931df2ed8b38d5ad8b6df25ef6f71a9657193d6a 20090616162007-28748-931df2ed8b38d5ad8b6df25ef6f71a9657193d6a.gz: gzip: 20090616162007-28748-931df2ed8b38d5ad8b6df25ef6f71a9657193d6a.gz: invalid compressed data--crc error
http://bugs.darcs.net/issue844 Some versions of darcs misuse gzip, causing checksum corruption. The corrupt gzip files can be "fixed" by recalculating the CRC; the attached heal-darcs.sh shows one such solution.
This corruption affects many (most?) CL darcs repos. It usually doesn't affect darcs itself (which ignores the checksums) but often causes problems with other tools. I used to notify people of this issue, but now just run heal-darcs and hope mismatched checksums weren't actually valid.
- Daniel